Python Coding Challenge - Question with Answer (ID -030226)

 

🔹 Step 1: Tuple creation

t = (10, 20, 30)

A tuple is created.
Tuples are immutable → you cannot change their values.

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🔹 Step 2: Loop starts

for i in t:

This means:

• First iteration → i = 10

• Second iteration → i = 20

• Third iteration → i = 30

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🔹 Step 3: Condition

if i == 20:
    i = 99

When i becomes 20, you assign:

i = 99

But ⚠️ this only changes the local variable i,
NOT the tuple.

It’s like:

i = 20
i = 99   # only variable changed, not original data

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🔹 Step 4: Print

print(t)

The tuple was never modified, so output is:

(10, 20, 30)

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 Key Concept (Very Important)

Loop variable does not modify immutable objects.

You changed:

• ❌ the variable

• Not the tuple

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❌ This will NEVER work on tuples

t[1] = 99   # Error! Tuples are immutable

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✅ Correct way (convert to list)

t = list(t)
t[1] = 99
t = tuple(t)
print(t)

Output:

(10, 99, 30)

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Interview One-Liner Answer:

Because tuples are immutable, changing the loop variable does not affect the original tuple.